Volume 20, Number 4
Newsletter of National Sustainable Agricultural Information Service: A program of the National Center for Appropriate Technology (NCAT). This issue of ATTRAnews is available online.
This high-density organic apple orchard in Pascoe, Washington, is trained on trellises in a "V" shape. The open centers of the trees permit efficient photosynthesis as well as extensive air circulation to reduce fungal diseases. Photo: Rex Dufour, NCAT
Meeting the Challenges of Growing Organic Fruit
Home Acres Orchard,
Adapted from an article by Tammy Hinman, NCAT Horticulture Specialist, in Apples: Organic Production Guide
When Pam Clevenger and Kurt Welborne began growing fruit in rural western Montana in 1990, there were lots of produce farms but no organic tree fruit production in the area, although historically lots of apples were grown in the region. Pam and Kurt say there is definitely a demand for organic fruit, but marginal growing conditions are the biggest limitation.
The region may experience hard early frosts, hard late frosts, or extended periods of warm weather in January. The farm is dependent on snowpack for irrigation, and in a dry year the irrigation water may run out in early August, when temperatures are often over 90° F. Since the weather is particularly hard on new trees, they use only semi-dwarf rootstock, the roots of which are more effective at foraging for water and withstanding high winds.
Pam and Kurt grow about 20 varieties of apples, three varieties of Asian pears, six varieties of European pears, and three varieties of apricots. They also grow tart cherries and plums for their own use. They say the Asian pears have extra boron demands but otherwise are trouble-free compared to apples. The pear trees are interspersed among the apples, which they believe helps keep their insect and disease problems down.
The farmers also use wildscaping, particularly around the perimeter of the orchard. The wildscaping has enhanced pollination, but also increased the number of birds that feed on apples.
For codling moth, Pam and Kurt rely primarily on Spinosad®, a biological control, along with pheromone emitters for mating disruption. They spray Bacillus thuringiensis several times in the spring for leaf rollers. They have brought in lacewings in past years to help control aphids, but now there seems to be a strong resident population that pretty much keeps the aphids in check. They use copper and lime sulfur for fire blight and scab.
Pam and Kurt have experimented with different fertility treatments over the years, including alfalfa pellets and feathermeal. Last summer the farmers cut hay from their own pastures and mulched their trees with a mixture of clover, alfalfa, and grass. They add sulfur regularly to the soil and spray boron, calcium, and zinc to boost these nutrients on their farm.
Interestingly, despite following organic practices, Home Acres Orchard is no longer certified organic. Pam and Kurt have joined with other growers in the region to form the Montana Sustainable Growers’ Union, which promotes its products under its own Homegrown label. They still get a premium price for their fruit and sell their products through two farmers markets, a local natural food store, and the Western Montana Growers Co-op.
Overall, says Kurt, "Some years you're lucky, some years you’re not." He and Pam note there are lots of rewards that aren’t monetary.
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Managing Pests and Diseases in Organic Orchards
Adapted from articles by NCAT Horticulture Specialists Guy Ames and Tammy Hinman
Apples are prone to attack by an impressive number of pests and diseases. Without effective management, the worst of these pests can be devastating — to the fruit, to the grower’s spirit, and to the bottom line.
To minimize or eliminate chemical inputs while keeping yields and profits sound, the grower must develop a detailed understanding of the orchard as a managed ecosystem. There is no substitute for direct observation and experience, along with a willingness to experiment. As the organic market for apples increases, more organic management options are available to growers.
Geographic and climatic considerations, cultivar selection, the local pest complex, market prices, production costs, and other factors all influence the design and viability of an organic system. Individual producers must try various tools and evaluate them according to efficacy, cost, production, marketing goals, and personal preferences.
What begins as a fragmented pest-by-pest set of tactics must gradually form an overall management plan in which the various strategies work together as much as possible. Obstacles to organic production include the following:
Cultural guidelines for controlling one pest may create conditions that favor another pest.
Many organic pest-control tactics tend to give highly variable results from location to location and from year to year.
Traditional local support services are often unable to provide much information or guidance.
The practices may be labor and/or capital intensive.
European and Asian Pears
In much of the United States, with the availability of fire-blight resistant cultivars, pears may be the easiest of the major tree fruits to produce organically or with minimal spraying.
Pear fertility requirements are not high. The trees are adapted to a wide range of climates and soils, but have fewer pest problems than other tree fruits. The orchards are subject to most of the same pests and diseases as apples, but usually to a considerably lesser degree. However, fire blight can still be a problem on pear trees all over the country.
Standard cultural considerations, such as pruning, planting, spacing, and thinning, are generally the same for organic and conventional growers. Most European pears are picked before they are fully ripe and are then allowed to ripen off the tree. The most widely grown varieties are Bartlett, Bosc, D'Anjou, Seckel, Magness, Maxine, Moonglow, and Comice.
In the last two to three decades, the Asian pear has joined the more familiar European pears in American orchards and the marketplace. Asian pears are generally round, crisp, and juicy, with flavors varying between sweet, bland, and pineapple-like.
The trees are cultivated in much the same way as European pears, but the fruit is allowed to ripen on the trees. Common cultivars include Shinseiki, Korean Giant, Shinko, Chojuro, Niitaka, Clear Moon, Shin-Li, and Tsu Li.
Intense disease and insect pressure makes peaches one of the most difficult tree fruits to produce organically. In parts of the arid West, commercial organic peach production is feasible when the grower adequately addresses brown rot, peach twig borers, and Oriental fruit moth.
In most of the East, organic production is greatly complicated by the plum curculio and brown rot. At present, there is virtually no significant organic peach production in the East. However, with new pest-management tools, organic peach production, or at least a more ecologically grounded system, is becoming far more plausible than it was just a few years ago. Meanwhile, low-spray production with limited use of the least-toxic synthetic inputs is a proven alternative for eastern growers.
Geographic Factors Affecting Disease and Pest Management
West of the "tree line" (which runs roughly from Fort Worth, Texas, to Fargo, North Dakota), a major insect pest of many tree fruits — the plum curculio — is not present. This fact, along with reduced disease pressure due to lower humidity, simplifies organic production of apples and other fruit in much of the West.
Growers in the eastern part of the country, on the other hand, must contend with the plum curculio and increased incidence of fungal diseases. Northeastern growers have the apple maggot as an additional major pest. In the Southeast, the various fruit rots can be especially troublesome.
The prognosis for eastern organic apple production is starting to look up, however. Through a combination of innovative pest-management strategies and diligent research, many of the issues associated with organic apple production in the East are beginning to be resolved.
Surround® WP, a kaolin-clay based pesticide, has dramatically changed the face of organic fruit production in the eastern United States. These control measures require intensive management, though, and growers need to account for additional pest-management time and expense in their enterprise budgets.
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Pest, Weed, and Fertility Benefits of Pastured Poultry in Orchards
by Rex Dufour, NCAT Agriculture Specialist
The weed seed bank on most farms is contained in the top few inches of the soil. Many insect pests also spend at least a part of their life cycle (generally, but not always the pupal stage) in the upper few inches of the soil. This is likely the reason that chickens evolved their scratching behavior — to search for small tidbits of food in the rich upper layers of the soil.
Farmers can use poultry to help manage insect pests and weeds in their orchards or cropping systems. Most orchard pests such as codling moth, plum curculio, fruit flies, thrips, and other lepidopteran pests (leaf rollers, leaf miners…it's a long list) spend a part of their life cycle in the "chicken-scratch depth" of the soil.
Certainly there are significant management considerations to having poultry in the orchard or field, such as how often to move the birds, the size and configuration of the moveable pens, and how to assure protection from predators. See ATTRA's many resources on poultry for more information about these questions, www.attra.ncat.org/attra-pub/poultry/.
In addition to pest-control benefits, chickens can provide much-needed fertility, particularly phosphorus, to soils. But the birds' presence needs to be managed to prevent phosphorus or nitrogen run-off.
A typical meat bird will provide 15 pounds of manure during its short life. The N-P-K value of this manure is about 40 cents/bird — not very much, unless you're raising a lot of birds or you're an organic farmer looking for nonchemical sources of soil nutrients. One laying hen will provide about 22 pounds of manure a year. The manure contributes to soil fertility and supports soil biology as an added benefit.
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Resources for Organic Fruit Producers
The Apple Grower and The Holistic Orchard by Michael Phillips and Twenty Years of Apple Production Under an Ecological Approach to Pest Management by Ron Prokopy are excellent guide books for transitioning to organic production.
Holistic Orchard Network shares sustainable fruit-growing techniques with an emphasis on orchard soil health. http://groworganicapples.com
North American Fruit Explorers offers services to members, such as fruit and nut interest groups, special consultants in various fields, and a good quarterly publication, Pomona. www.nafex.org
Good Fruit Grower magazine has been published by the Washington State Fruit Commission since 1946. www.goodfruit.com
American/Western Fruit Grower magazine and website provide news on all aspects of the fruit-growing industry. www.growingproduce.com
Fruit Growers News is based in Michigan but reports on fruit developments around the world. http://fruitgrowersnews.com
ATTRA Resources for Fruit Growers
The following ATTRA publications and resources include useful information for fruit growers. These and many more can be found in the horticulture section of ATTRA’s website, www.attra.ncat.org/horticultural.html. Call 800-346-9140 for a printed copy. Prices vary and many resources are free.
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ATTRAnews is the newsletter of the National Sustainable Agriculture Information Service. The free newsletter is distributed free throughout the United States to farmers, ranchers, Cooperative Extension agents, educators, and others interested in sustainable agriculture. ATTRA is funded through the USDA Rural Business-Cooperative Service and is a project of the National Center for Appropriate Technology (NCAT), a private, non-profit organization that since 1976 has helped people by championing small-scale, local and sustainable solutions to reduce poverty, promote healthy communities, and protect natural resources.
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